Two Spaceships & Light: Measuring Speed from Earth

[keepitmoving]

two spaceships send a light beam toward Earth at the moment that they pass each other, one sends light backward toward us and one sends light forward toward us.
On Earth we measure the light speed as equal but let's back up to when the two lights were emitted. What speed would we measure for the two lights?

 

[Vanadium 50]

c

They always measure c.